1. Field of the Invention
The present invention relates to computer networks, and more particularly to Voice over Internet protocol (VoIP) networks using Session Initiation Protocol (SIP), for enabling applications to integrate VoIP.
2. Description of the Related Art
Session Initiation Protocol (SIP) is emerging as the vehicle for enabling VoIP in enterprise and carrier networks. So far, desktop applications and email clients, or web-browsers were not enabled with voice or are decoupled from voice applications.
SIP or Session Initiation Protocol is gaining ground both within enterprise networks and service provider networks as the vehicle for providing Voice Over IF (VoIP) and new multimedia services. Most VoIP applications today are stand-alone applications such as an IF Softphone, which runs on a user laptop allowing a user to place and receive voice calls. In addition, SIP is also in use for supporting Instant Messages between a client machine and a server machine. However, the SIP support is bundled with individual applications such an IM client or an IP softphone, and individual applications must run their own SIP support. This may create problems when multiple SIP protocol stacks are operational, e.g. SIP often uses port 5060 for its operation. If the bundled SIP stack within an application uses this port, it would mean that no other SIP application will be able to run on this port. More importantly, this is wasteful of system resources.
As the adoption of SIP based services grows, there is a need for desktop applications to invoke SIP in a uniform way. A further need exists for a framework for enabling applications with VoIP using SIP (Session Initiation Protocol).